Heat transfer enhancement by velocity field excitation for an impinging round jet

Abstract

In this paper the effect of inlet velocity field excitation on heat transfer by an impinging round jet has been investigated using Large Eddy Simulations (LESs). The time-averaged bulk Reynolds number (Re) of the jet for all cases is 23,000 and the dimensionless jet’s outlet-to-target wall distance (H) is two diameters. The Strouhal number (St) corresponding to the preferred mode of the unexcited jet is estimated through LES. The jet is then excited at different frequencies. The amplitude of excitation is kept at 50% of the bulk inlet velocity. It has been found that the excitation of the jet velocity field causes only large-scale excitation. Heat transfer enhancement is found to be possible with inlet velocity field excitation.